To the Popes and those who had the power and interest of the Church most at heart the problem appeared in quite a different light. It was a question of steering Christian dogma between the Scylla of pantheism and the Charybdis of materialism and its logical conclusion, scepticism. Thus, throughout the history of Scholasticism we have to do with a sort of triangle of intellectual forces: Realism and Nominalism fighting a five hundred years’ war, and the Church, in its official capacity, anxiously endeavouring to hold the balance between them. One wonders whether the three parties to this ancient dispute may not have found symbolic expression in Tweedledum, Tweedledee, and the “Monstrous Crow” of nursery legend. But it is no disparagement of the intellects of that day to say that to us the chief interest of their polemics lies in the many new and accurate instruments of thought with which they provided us. The common word _accident_ is an excellent example. We use it every day without realizing that it was only imported from Latin by the indefatigable efforts of the Schoolmen to reconcile the doctrine of Realism with the Catholic dogma of Transubstantiation. The _accidents_, when they first came into the English language, meant that part of the sacred bread and wine which remained after the _substance_ had been transmuted into the body and blood of Christ. On the whole it is a safe rule to assume that those who speak most contemptuously of such thinkers as Thomas Aquinas and Duns Scotus are the nearest modern representatives of their own idea of what these Schoolmen were; that is to say, they are those whose imaginations are most completely imprisoned within the intellectual horizon of the passing age. Much fun has been made of medieval philosophy for discussing such matters as how many angels can stand on the point of a needle, and whether Christ could have performed His cosmic mission equally well if He had been incarnated as a pea instead of as a man. The growth of a rudimentary historical sense has, it is true, made it fashionable lately to take these ancient thinkers a little more seriously, but it is still the rarest thing to find a philosopher or a psychologist who fully comprehends that he is consuming the fruits of this long, agonizing struggle to state the exact relation between spirit and matter, every time he uses such key-words of thought as _absolute_, _actual_, _attribute_, _cause_, _concept_, _deduction_, _essence_, _existence_, _intellect_, _intelligence_, _intention_, _intuition_, _motive_, _potential_, _predicate_, _substance_, _tendency_, _transcend_; _abstract_ and _concrete_, _entity_ and _identity_, _matter_ and _form_, _quality_ and _quantity_, _objective_ and _subjective_, _real_ and _ideal_, _general_, _special_, and _species_, _particular_, _individual_, and _universal_. ‘Free will’ is the translation of a Latin phrase first used by a Church Father, and ‘argumentum ad hominem’ is an example