Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.
- I like to define biology as the history of the earth and all its life — past, present, and future. To understand biology is to understand that all life is linked to the earth from which it came; it is to understand that the stream of life, flowing out of the dim past into the uncertain future, is in reality a unified force, though composed of an infinite number and variety of separate lives.
- Rachel Carson Preface to Humane Biology Projects (1961) by the Animal Welfare Institute
- The ultimate aim of the modern movement in biology is in fact to explain all biology in terms of physics and chemistry.
- Francis Crick (1966) Of Molecules and Men. p. 10.
- What is found in biology is mechanisms, mechanisms built with chemical components and that are often modified by other, later, mechanisms added to the earlier ones. While Occam's razor is a useful tool in the physical sciences, it can be a very dangerous implement in biology.
- Francis Crick (1988) What Mad Pursuit
- [A]ll of modern biology is an affirmation of this relatedness of the many species of living things and of their gradual divergence from one another over the course of time.
- Helena Curtis and N. Sue Barnes Biology 5th ed. 1989, Worth Publishers, p. 972
- Seen in the light of evolution, biology is, perhaps, intellectually the most satisfying and inspiring science. Without that light it becomes a pile of sundry facts -- some of them interesting or curious but making no meaningful picture as a whole.
- Theodosius Dobzhansky (1972) "Nothing in Biology Makes Sense Except in the Light of Evolution"
- Biology is not physics, because organisms are such complex physical objects, and sociology is not biology because human societies are made by self-conscious organisms. By pretending to a kind of knowledge that it cannot achieve, social science can only engender the scorn of natural scientists and the cynicism of the humanists.
- Richard Lewontin (1995) "Sex, Lies, and Social Science" in New York Review of Books (4/20/95)
- When you study science, and especially these realms of the biology of what makes us human, what's clear is that every time you find out something, that brings up ten new questions, and half of those are better questions than you started with.
- Robert Sapolsky (2003) Emperor Has No Clothes Award acceptance speech
About biologists 
- Today, nearly all biologists acknowledge that evolution is a fact.
- Neil A. Campbell, Biology 2nd ed., 1990, Benjamin/Cummings, p. 434
- Today, the central and still fascinating questions for biologists concern the mechanisms by which evolution occurs."
- Helena Curtis and N. Sue Barnes, Biology 5th ed. 1989, Worth Publishers, p. 972
- Any competent biologist is aware of a multitude of problems yet unresolved and of questions yet unanswered. After all, biologic research shows no sign of approaching completion; quite the opposite is true. Disagreements and clashes of opinion are rife among biologists, as they should be in a living and growing science. Antievolutionists mistake, or pretend to mistake, these disagreements as indications of dubiousness of the entire doctrine of evolution. Their favorite sport is stringing together quotations, carefully and sometimes expertly taken out of context, to show that nothing is really established or agreed upon among evolutionists. Some of my colleagues and myself have been amused and amazed to read ourselves quoted in a way showing that we are really antievolutionists under the skin.
- More attention to the History of Science is needed, as much by scientists as by historians, and especially by biologists, and this should mean a deliberate attempt to understand the thoughts of the great masters of the past, to see in what circumstances or intellectual milieu their ideas were formed, where they took the wrong turning or stopped short on the right track.
- Ronald Fisher 1959 "Natural selection from the genetical standpoint". Australian Journal of Science 22, 16-17, .
- No biologist today would think of submitting a paper entitled "New evidence for evolution;" it simply has not been an issue for a century.
- Douglas J. Futuyma, Evolutionary Biology, 2nd ed., 1986, Sinauer Associates, p. 15
- What good men most biologists are, the tenors of the scientific world — temperamental, moody, lecherous, loud-laughing, and healthy. Your true biologist will sing you a song as loud and off-key as will a blacksmith, for he knows that morals are too often diagnostic of prostatitis and stomach ulcers. Sometimes he may proliferate a little too much in all directions, but he is as easy to kill as any other organism, and meanwhile he is very good company, and at least he does not confuse a low hormone productivity with moral ethics.