William Whewell

When alterations in technical terms become necessary, it is desirable that the new term should contain in its form some memorial of the old one.

[P]hilological analogies are to be preserved if possible, but modified according to scientific convenience.

In forming a Terminology, words may be invented when necessary, but they cannot be conveniently borrowed from casual or arbitrary circumstances.

The fundamental terms of a system of Nomenclature may "be conveniently borrowed from casual or arbitrary circumstances.

If terms are systematically good, they are not to be rejected because they are etymologically inaccurate.

Terms which imply theoretical views are admissible, as far as the theory is proved.

New terms and changes of terms, which are not needed in order to express truth, are to be avoided.

Terms must be constructed and appropriated so as to be fitted to enunciate simply and clearly true general propositions.

It is better to form new words as technical terms, than to employ old ones in which the last three Aphorisms cannot be complied with.

When common words are appropriated as technical terms, this must be done so that they are not ambiguous in their application.

When common words are appropriated as technical terms, their meaning may be modified, and must be rigorously fixed.

When common words are appropriated as technical terms, their meaning and relations in common use should be retained as far as can conveniently be done.

In framing scientific terms, the appropriation of old words is preferable to the invention of new ones.

In the Ancient Period of Science, Technical Terms were formed in three different ways:—by appropriating common words and fixing their meaning;—by constructing terms containing a description;—by constructing terms containing reference to a …

The Construction of the Conception very often includes, in a great measure, the Determination of the Magnitudes. The true construction of the conception is frequently suggested by some hypothesis; and in these cases, the hypothesis may be …

'Natural History' ought to form a part of intellectual education, in order to correct certain prejudices which arise from cultivating the intellect by means of mathematics alone and in order to lead the student to see that the division of …

The distinction of Fact and Theory is only relative. Brute animals have a practical knowledge of relations of space and force; but they have no knowledge of Geometry or Mechanicks.

The Logic of Induction is the 'Criterion of Truth' inferred from Facts, as the Logic of Deduction is the 'Criterion of Truth' deduced from necessary Principle. In Art, Truth is a means to an end; in Science, it is the only end.

The 'Logic of Induction' consists in stating the Facts and the Inference in such a manner, that the evidence of the Inference is manifest; just as the Logic of Deduction consists in stating the Premises and the Conclusion in such a manner …

When a series of progressive numbers is given as the result of observation, it may generally be reduced to law by combinations of arithmetical and geometrical progressions. A true formula for a progressive series of numbers cannot commonly …

Facts are the materials of science, but all Facts involve Ideas. Since, in observing Facts, we cannot exclude Ideas, we must, for the purposes of science, take care that the Ideas are clear and rigorously applied.

Discovery depends upon the previous cultivation or natural clearness of the appropriate Idea, and therefore no discovery is the work of accident.

The two processes by which Science is constructed are the 'Explication of Conceptions' and the 'Colligation of Facts'.

The Palaetiological Sciences point backwards with lines which are broken, but which all converge to the 'same' invisible point: and this point is the Origin of the Moral and Spiritual, as well as of the natural world.