nd parts are wholly the
work of Aquinas, but of the third part only the first ninety quaestiones
are his; the rest of it was finished in accordance with his designs. The
first book, after a short introduction upon the nature of theology as
understood by Aquinas, proceeds in 119 questions to discuss the nature,
attributes and relations of God; and this is not done as in a modern
work on theology, but the questions raised in the physics of Aristotle
find a place alongside of the statements of Scripture, while all
subjects in any way related to the central theme are brought into the
discourse. The second part is divided into two, which are quoted as
_Prima Secundae_ and _Secunda Secundae_. This second part has often been
described as ethic, but this is scarcely true. The subject is man,
treated as Aristotle does, according to his [Greek: telos], and so
Aquinas discusses all the ethical, psychological and theological
questions which arise; but any theological discussion upon man must be
mainly ethical, and so a great proportion of the first part, and almost
the whole of the second, has to do with ethical questions. In his
ethical discussions (a full account of which is given under ETHICS)
Aquinas distinguishes theological from natural virtues and vices; the
theological virtues are faith, hope and charity; the natural, justice,
prudence and the like. The theological virtues are founded on faith, in
opposition to the natural, which are founded on reason; and as faith
with Aquinas is always belief in a proposition, not trust in a personal
Saviour, conformably with his idea that revelation is a new knowledge
rather than a new life, the relation of unbelief to virtue is very
strictly and narrowly laid down and enforced. The third part of the
_Summa_ is also divided into two parts, but by accident rather than by
design. Aquinas died ere he had finished his great work, and what has
been added to complete the scheme is appended as a _Supplementum Tertiae
Partis_. In this third part Aquinas discusses the person, office and
work of Christ, and had begun to discuss the sacraments, when death put
an end to his labours.

The purely philosophical theories of Aquinas are explained in the
article SCHOLASTICISM. In connexion with the problem of universals, he
held that the diversity of individuals depends on the quantitative
division of matter (_materia signata_), and in this way he attracted the
criticism of the Scotists, who pointed out t