Philosophy of chemistry
Encyclopedia
The philosophy
of chemistry
considers the methodology
and underlying assumptions of the science
of chemistry. It is explored by philosophers, chemists, and philosopher-chemist teams. For much of its history, philosophy of science
has been dominated by the philosophy of physics
, but the philosophical questions that arise from chemistry have received increasing attention since the latter part of the 20th century.
s and molecule
s are often assumed to be the fundamental units of chemical theory, but traditional descriptions of molecular structure and chemical bond
ing fail to account for the properties of many substances, including metals
and metal complexes and aromaticity
.
Additionally, chemists frequently use non-existent chemical entities like resonance structures
to explain the structure and reactions of different substances; these explanatory tools use the language and graphical representations of molecules to describe the behavior of chemicals and chemical reactions that in reality do not behave as straightforward molecules.
Some chemists and philosophers of chemistry prefer to think of substances, rather than microstructures, as the fundamental units of study in chemistry. There is not always a one-to-one correspondence between the two methods of classifying substances. For example, many rocks exist as mineral complexes composed of multiple ions that do not occur in fixed proportions or spatial relationships to one another.
A related philosophical problem is whether chemistry is the study of substances or reactions. Atoms, even in a solid, are in perpetual motion and under the right conditions many chemicals react spontaneously to form new products. A variety of environmental variables contribute to a substance's properties, including temperature and pressure, proximity to other molecules and the presence of a magnetic field. As Schummer puts it, “Substance philosophers define a
chemical reaction by the change of certain substances, whereas process philosophers define a substance by its characteristic chemical reactions.”
Philosophers of chemistry discuss issues of symmetry
and chirality
in nature. Organic
(i.e., carbon
-based) molecule
s are those most often chiral. Amino acid
s, nucleic acid
s and sugar
s, all of which are found exclusively as a single enantiomer
in organisms, are the basic chemical units of life
. Chemists, biochemists
, and biologists alike debate the origins of this homochirality
. Philosophers debate facts regarding the origin of this phenomenon, namely whether it emerged contingently, amid a lifeless racemic
environment or if other processes were at play. Some speculate that answers can only be found in comparison to extraterrestrial life
, if it is ever found. Other philosophers question whether there exists a bias toward assumptions of nature as symmetrical, thereby causing resistance to any evidence to the contrary.
One of the most topical issues is determining to what extent physics, specifically, quantum mechanics, explains chemical phenomena. Can chemistry, in fact, be reduced to physics as has been assumed by many, or are there inexplicable gaps? Some authors have recently suggested that a number of difficulties exist in the reductionist program, notwithstanding our increasing knowledge of the microcosmic realm. The noted philosopher of science, Karl Popper
, among others, predicted as much.
. While astronomers have to get along without experimenting directly on the distant objects of their attention, and biologists have to experiment within ethical and legal restraints on more available objects, chemistry conforms to, and indeed gave rise to, textbook explanations of what constitutes the scientific method
.
One theme arising from chemical experiments is the value of ambiguity
as a spur to the type of science that chemists do. Emily R. Grosholz and Roald Hoffmann
, for example, have argued that equivocations in chemistry have helped bridge the gap between experiment and theory, thereby advancing the field. Such an argument challenges preconceptions to the effect that the more fully concepts are clarified, the more useful they will prove.
philosopher Jaap van Brakel, who wrote The Philosophy of Chemistry in 2000, and the Maltese
philosopher-chemist Eric Scerri, editor of the journal "Foundations of Chemistry" and author of Normative and Descriptive Philosophy of Science and the Role of Chemistry in Philosophy of Chemistry, 2004, among other articles. Scerri is especially interested in the philosophical foundations of the periodic table
, and how physics and chemistry intersect in relation to it, which he contends is not merely a matter for science, but for philosophy.
Although in other fields of science students of the method are generally not practitioners in the field, in chemistry (particularly in synthetic organic chemistry) intellectual method and philosophical foundations are often explored by investigators with active research programmes. Elias James Corey
developed the concept of "retrosynthesis" published a seminal work "the logic of chemical synthesis" which deconstructs these thought processes and speculates on computer-assisted synthesis. Other chemists such as K.C. Nicolaou (co-author of Classics in Total Synthesis) have followed in his lead.
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
of chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
considers the methodology
Methodology
Methodology is generally a guideline for solving a problem, with specificcomponents such as phases, tasks, methods, techniques and tools . It can be defined also as follows:...
and underlying assumptions of the science
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
of chemistry. It is explored by philosophers, chemists, and philosopher-chemist teams. For much of its history, philosophy of science
Philosophy of science
The philosophy of science is concerned with the assumptions, foundations, methods and implications of science. It is also concerned with the use and merit of science and sometimes overlaps metaphysics and epistemology by exploring whether scientific results are actually a study of truth...
has been dominated by the philosophy of physics
Philosophy of physics
In philosophy, the philosophy of physics studies the fundamental philosophical questions underlying modern physics, the study of matter and energy and how they interact. The philosophy of physics begins by reflecting on the basic metaphysical and epistemological questions posed by physics:...
, but the philosophical questions that arise from chemistry have received increasing attention since the latter part of the 20th century.
Foundations of chemistry
Major philosophical questions arise as soon as one attempts to define chemistry and what it studies. AtomAtom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
s and molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s are often assumed to be the fundamental units of chemical theory, but traditional descriptions of molecular structure and chemical bond
Chemical bond
A chemical bond is an attraction between atoms that allows the formation of chemical substances that contain two or more atoms. The bond is caused by the electromagnetic force attraction between opposite charges, either between electrons and nuclei, or as the result of a dipole attraction...
ing fail to account for the properties of many substances, including metals
Metallic bond
Metallic bonding is the electrostatic attractive forces between the delocalized electrons, called conduction electrons, gathered in an "electron sea", and the positively charged metal ions...
and metal complexes and aromaticity
Aromaticity
In organic chemistry, Aromaticity is a chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August...
.
Additionally, chemists frequently use non-existent chemical entities like resonance structures
Resonance (chemistry)
In chemistry, resonance or mesomerism is a way of describing delocalized electrons within certain molecules or polyatomic ions where the bonding cannot be expressed by one single Lewis formula...
to explain the structure and reactions of different substances; these explanatory tools use the language and graphical representations of molecules to describe the behavior of chemicals and chemical reactions that in reality do not behave as straightforward molecules.
Some chemists and philosophers of chemistry prefer to think of substances, rather than microstructures, as the fundamental units of study in chemistry. There is not always a one-to-one correspondence between the two methods of classifying substances. For example, many rocks exist as mineral complexes composed of multiple ions that do not occur in fixed proportions or spatial relationships to one another.
A related philosophical problem is whether chemistry is the study of substances or reactions. Atoms, even in a solid, are in perpetual motion and under the right conditions many chemicals react spontaneously to form new products. A variety of environmental variables contribute to a substance's properties, including temperature and pressure, proximity to other molecules and the presence of a magnetic field. As Schummer puts it, “Substance philosophers define a
chemical reaction by the change of certain substances, whereas process philosophers define a substance by its characteristic chemical reactions.”
Philosophers of chemistry discuss issues of symmetry
Symmetry
Symmetry generally conveys two primary meanings. The first is an imprecise sense of harmonious or aesthetically pleasing proportionality and balance; such that it reflects beauty or perfection...
and chirality
Chirality (chemistry)
A chiral molecule is a type of molecule that lacks an internal plane of symmetry and thus has a non-superimposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom....
in nature. Organic
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...
(i.e., carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
-based) molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s are those most often chiral. Amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s, nucleic acid
Nucleic acid
Nucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...
s and sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
s, all of which are found exclusively as a single enantiomer
Enantiomer
In chemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable , much as one's left and right hands are the same except for opposite orientation. It can be clearly understood if you try to place your hands one over the other without...
in organisms, are the basic chemical units of life
Life
Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...
. Chemists, biochemists
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
, and biologists alike debate the origins of this homochirality
Homochirality
Homochirality is a term used to refer to a group of molecules that possess the same sense of chirality. Molecules involved are not necessarily the same compound, but similar groups are arranged in the same way around a central atom. In biology homochirality is found in the chemical building blocks...
. Philosophers debate facts regarding the origin of this phenomenon, namely whether it emerged contingently, amid a lifeless racemic
Racemic
In chemistry, a racemic mixture, or racemate , is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule. The first known racemic mixture was "racemic acid", which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid.- Nomenclature :A...
environment or if other processes were at play. Some speculate that answers can only be found in comparison to extraterrestrial life
Extraterrestrial life
Extraterrestrial life is defined as life that does not originate from Earth...
, if it is ever found. Other philosophers question whether there exists a bias toward assumptions of nature as symmetrical, thereby causing resistance to any evidence to the contrary.
One of the most topical issues is determining to what extent physics, specifically, quantum mechanics, explains chemical phenomena. Can chemistry, in fact, be reduced to physics as has been assumed by many, or are there inexplicable gaps? Some authors have recently suggested that a number of difficulties exist in the reductionist program, notwithstanding our increasing knowledge of the microcosmic realm. The noted philosopher of science, Karl Popper
Karl Popper
Sir Karl Raimund Popper, CH FRS FBA was an Austro-British philosopher and a professor at the London School of Economics...
, among others, predicted as much.
Methodology
Chemistry is in a sense the paradigmatic laboratory science, one that predates both experimental and theoretical physicsPhysics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
. While astronomers have to get along without experimenting directly on the distant objects of their attention, and biologists have to experiment within ethical and legal restraints on more available objects, chemistry conforms to, and indeed gave rise to, textbook explanations of what constitutes the scientific method
Scientific method
Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...
.
One theme arising from chemical experiments is the value of ambiguity
Ambiguity
Ambiguity of words or phrases is the ability to express more than one interpretation. It is distinct from vagueness, which is a statement about the lack of precision contained or available in the information.Context may play a role in resolving ambiguity...
as a spur to the type of science that chemists do. Emily R. Grosholz and Roald Hoffmann
Roald Hoffmann
Roald Hoffmann is an American theoretical chemist who won the 1981 Nobel Prize in Chemistry. He currently teaches at Cornell University in Ithaca, New York.-Escape from the Holocaust:...
, for example, have argued that equivocations in chemistry have helped bridge the gap between experiment and theory, thereby advancing the field. Such an argument challenges preconceptions to the effect that the more fully concepts are clarified, the more useful they will prove.
Philosophers of chemistry
Several philosophers and scientists have focused on the philosophy of chemistry in recent years, notably, the DutchNetherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
philosopher Jaap van Brakel, who wrote The Philosophy of Chemistry in 2000, and the Maltese
Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
philosopher-chemist Eric Scerri, editor of the journal "Foundations of Chemistry" and author of Normative and Descriptive Philosophy of Science and the Role of Chemistry in Philosophy of Chemistry, 2004, among other articles. Scerri is especially interested in the philosophical foundations of the periodic table
Periodic table
The periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...
, and how physics and chemistry intersect in relation to it, which he contends is not merely a matter for science, but for philosophy.
Although in other fields of science students of the method are generally not practitioners in the field, in chemistry (particularly in synthetic organic chemistry) intellectual method and philosophical foundations are often explored by investigators with active research programmes. Elias James Corey
Elias James Corey
Elias James Corey is an American organic chemist. In 1990 he won the Nobel Prize in Chemistry "for his development of the theory and methodology of organic synthesis", specifically retrosynthetic analysis...
developed the concept of "retrosynthesis" published a seminal work "the logic of chemical synthesis" which deconstructs these thought processes and speculates on computer-assisted synthesis. Other chemists such as K.C. Nicolaou (co-author of Classics in Total Synthesis) have followed in his lead.
Review Articles
- Philosophy of Chemistry article on the Stanford Encyclopedia of Philosophy
Journals
- Foundations of Chemistry, an international peer-reviewed journal for History and Philosophy of Chemistry as well as Chemical Education published by Springer.
- Hyle: International Journal for Philosophy of Chemistry, an English-language peer-reviewed journal associated with the University of Karlsruhe, GermanyGermanyGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
.
Books
- Philosophy of Chemistry, J. van Brakel, Leuven University Press, 2000. ISBN 9-05867-063-5
- Philosophy of Chemistry : Synthesis of a New Discipline, Davis Baird, Eric Scerri, Lee McIntyre (eds.), Dordrecht: Springer, 2006. ISBN 1402032560
- The Periodic Table: Its Story and Its Significance, E.R. Scerri, Oxford University Press, New York, 2006. ISBN 0195305736
- Of Minds and Molecules: New Philosophical Perspectives on Chemistry, 'Nalini Bhushan and Stuart Rosenfeld (eds.), Oxford University PressOxford University PressOxford University Press is the largest university press in the world. It is a department of the University of Oxford and is governed by a group of 15 academics appointed by the Vice-Chancellor known as the Delegates of the Press. They are headed by the Secretary to the Delegates, who serves as...
, 2000, Reviewed by Michael Weisberg