What precedes refers to the immediate constituents of compound essences. It is evident that every immediate principle, which is a complete being, involves other principles. Hence all compound essences imply some principles which are _proximate_, and others which are _remote_. The remote are those by which every primitive component is itself constituted in its individual reality, and from which the components derive their real aptitude to become the material, the formal, or the efficient principle of the compound essence. Principles of accidental compounds. We have hitherto shown that all physical beings, whether physically simple or physically complex, involve in their constitution an act, a term, and a formal complement. Nothing more is required to conclude that no physical being can be conceived of as an act without its term, or a term without its act, or a formal actuality not resulting from the concurrence of an act and its suitable term. From this it immediately appears that accidents and accidental modes are not physical beings, and that their existence is necessarily dependent on the existence of some other thing of which they are the appurtenances. An accident, properly so called, is _an act having no term of its own_, and, therefore, having no metaphysical essence and no possibility of a separate existence. Accordingly, the term of which it is in need must be supplied by a distinct being already existing in nature; and this is called _the subject_ of the accidental act. Hence no accidental act can be conceived to be without a subject. And here we must reflect that, as the _first_ actuation of an essential term by its essential act has for its result the actual _existence_ of the individual being, so also any _second_, or accidental, actuation of the term by an accidental act has for its result an actual _mode of existing_ of the same individual being. From this plain truth we infer that a distinction is to be made between _accidental acts_, which are properly accidents, and _accidental modes_, which are only accidentalities. An accident, properly speaking, is that which causes the subject to acquire an accidental actuality, and is always an act; whilst the accidental mode is not an act, but an accidental actuality which results in the subject from the reception of the accidental act.