He begins by showing that there has been an unfortunate neglect of one important factor in the case—a factor whose reality is frankly admitted by both parties. This central, incontestable fact is the _idea_ of freedom. This idea, according to Fouillée, arises in us as the result Of a combination of various psychological factors, such as notions of diversity, possibility, with the tendency to action arising from the notion of action, which thus shows itself as a force. The combination of these results in the genesis of the idea of freedom. Now the stronger this idea of freedom is in our minds the more we make it become a reality. It is an “idea-force” which by being thought tends to action and thus increases in power and fruitfulness. The idea of freedom becomes, by a kind of determinism, more powerful in proportion to the degree with which it is acted upon. Determinism thus reflects upon itself and in a curious way turns to operate against itself. This directing power of the idea of freedom cannot be denied even by the most rigorous upholders of determinism. They at least are forced to find room in their doctrine for _the idea_ of freedom and its practical action on the lives of men, both individually and in societies. The vice of the doctrines of determinism has been the refusal to admit the reality of the liberating idea of freedom, which is tending always to realise itself. The belief in freedom is, therefore, Fouillée claims, a powerful force in the world. Nothing is a more sure redeemer of men and societies from evil ways than the realisation of this idea of freedom. So largely is this the case that indeed the extinction of the _belief_ in freedom would, he argues, not differ much in consequence from the finding that freedom was an illusion, or, if it be a fact, its abolition. Having thus rectified the doctrine of determinism by including a place within it for _the idea_ of freedom, Fouillée proceeds by careful analysis to show the error of belief in freedom understood as that of an indifferent will. This raises as many fallacious views as that of a determinism bereft of the idea of freedom. The capricious and indifferent liberty he rejects, and in so doing shows us the importance of the intelligent power of willing, and also reaffirms the determinists’ thesis of inability to do certain things. The psychology of character shows us a determined freedom, and in the intelligent personality a reconciliation of freedom and determinism is seen to be effected. Fouillée shows that if it were not true that very largely what we have been makes us what we are, and that what we are determines our future actions, then education, moral guidance, laws and social sanctions would all be useless. Indifferentism in thought is the reversal of all thought.