Naturalism and Agnosticism is concerned to examine the presuppositions of popular science and its foreclosing of theistic inquiries. Ultimately it culminates in a defence of idealism (spiritualistic monism), which Ward holds, is required for any kind of exposition of theism. The first volume is concerned with the ‘real principles’ of natural science, and is devoted to the discussions of the Mechanical Theory and the Theory of Evolution.

Volume 1 consists in two parts (from five parts which make up the whole series—Volume II contains parts III—V). Part I of the lectures constitutes an investigation into naturalism under the Mechanical Theory of Nature. In Lectures II and III Ward discusses Abstract Dynamics (as first developed by Laplace) and the relation of this account to actual phenomena. Mach''s criticism of the account proves to set mechanical theory against itself and make its unconditional statements e.g. the principle of the Conservation of Mass, appear unwarrantable. Lectures IV and V discuss molecular mechanics beginning (in Lecture IV) with a debate between Clerk Maxwell and Clifford on the evidence for molecules, before discussing the notion of evolution as applied to the molecule, followed by the notion of the ether and some reactions to it (in particular from Professors Drude and K. Pearson). In Lecture V, ideals of matter under molecular mechanics are discussed and, in particular, the move by Boscovich and the French from the old atomism to dynamical atomism which is ultimately resolved into the kinetic theory. The kinetic ideal (also discussed under the ‘Theory of Energy’ in the concluding lecture of the first part — Lecture VI) demonstrates how the objects of mechanical theory are at best ‘fictions of the understanding’. Finally (Lecture VI), Ward closes the first part of his series with a discussion of the theory of energy where two questions are asked and answered 1) What is energy?, and 2) what is the Conservation of Energy? Among the authors discussed on the first matter are Tait, Helmholtz and Duhem, while the second question examines the metaphysical and ontological assumptions of the theory (of conservation of energy).

By means of his examination of the mechanical theory, Ward hopes to have done enough in Part I to show that Laplace''s confidence regarding what can count as an ontological object is, at least, confused.

Part II of the series looks at the theory of evolution. The first three lectures (VII, VIII and IX) are tied up with Herbert Spencer''s interpretation of evolution under its understanding as a mechanical process. In Lecture VII Spencer''s belief that the universe is alternately evolved and dissolved is examined and found wanting in light of the doctrine of the dissipation of energy. Further, limitations introduced by Lord Kelvin, Helmholtz and Maxwell reveal and two alternatives equally compatible with his doctrine which, ultimately, Spencer is identified as confounding. In Lecture VIII the principles and procedures of Spencer’s interpretation, along with some matters arising from them are examined, before, in Lecture IX it is concluded that Spencer errs in passing from Life (organic) to Mind (inorganic). The final lecture in Part II (X) takes up the Lamarckian, Darwinian and ultra-Darwinian (biological) theories of evolution and the attempts made therein to assimilate the biological with the physical, whilst addressing the question of purpose in biological evolution. Ultimately, entirely mechanistic natural selection is found unsatisfactory in accounting for biological evolution and the universe. A teleological account must accompany the mechanistic and order in the universe must be attributed to both life and mind. Nevertheless, the problem of the relation of mind to mechanism remains and it is to this issue that Ward turns in the second Volume.