VOLUME I.

LONDON: JOHN W. PARKER AND SON, WEST STRAND. 1858.

{{v}} PREFACE TO THIS EDITION.

THE Chapters now offered to the Reader were formerly published as a portion of _The Philosophy of the Inductive Sciences, founded upon their History_: but the nature and subject of these Chapters are more exactly described by the present title, _The History of Scientific Ideas_. For this part of the work is mainly historical, and was, in fact, collected from the body of scientific literature, at the same time that the _History of the Inductive Sciences_ was so collected. The present work contains the history of Science so far as it depends on _Ideas_; the former work contains the same history so far as it is derived from _Observation_. The leading features in _that_ were Theories inferred from Facts; the leading features of _this_ are Discussions of Theories tending to make them consistent with the conditions of human thought.

The Ideas of which the History is here given are mainly the following: _Space_, _Time_, _Number_, _Motion_, _Cause_, _Force_, _Matter_, _Medium_, _Intensity_, _Scale_, _Polarity_, _Element_, _Affinity_, _Substance_, _Atom_, _Symmetry_, _Likeness_, _Natural Classes_, _Species_, _Life_, _Function_, _Vital Forces_, _Final_ {vi} _Causes_, _Historical Causation_, _Catastrophe and Uniformity_, _First Cause_.

The controversies to which the exact fixation of these Ideas and their properties have given occasion form a large and essential part of the History of Science: but they also form an important part of the Philosophy of Science, for no Philosophy of Science can be complete which does not solve the difficulties, antitheses, and paradoxes on which such controversies have turned. I have given a survey of such controversies, generally carried from their earliest origin to their latest aspect; and have stated what appeared to me the best solution of each problem. This has necessarily involved me in much thorny metaphysics; but such metaphysics is a necessary part of the progress of Science. The human mind deriving its knowledge of Truth from the observation of nature, cannot evade the task of determining at every step how Truth is consistent with itself. This is the Metaphysics of Progressive Knowledge, and this is the matter of this present History.

Of the remaining part of what was formerly published as the Philosophy of the Inductive Sciences, an additional part, described in the Introduction to the present work, will shortly be published.

TRINITY LODGE, _May_ 24, 1858.

ERRATUM, p. 157, l. 11 from top, _for_ sciences _read_ science.

CONTENTS OF THE FIRST VOLUME.

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