Love works in a circle, for the beloved moves the lover by stamping a likeness, and the lover then goes out to hold the beloved inreality. Who first was the beginning now becomes the end of motion.
Thomas AquinasThe soul, which is the first principle of life, is not a body, but the act of a body; just as heat, which is the principle of calefaction, is not a body, but an act of a body.
Thomas AquinasFor it is necessary in every practical science to proceed in a composite (i.e. deductive) manner. On the contrary in speculative science, it is necessary to proceed in an analytical manner by breaking down the complex into elementary principles.
Thomas AquinasIt is altogether unlawful to kill oneself... Wherefore suicide is contrary to the inclination of nature, and to charity whereby every man should love himself... Life is God's gift to man, and is subject to His power, Who kills and makes to live. Hence whoever takes his own life, sins against God... for it belongs to God alone to pronounce sentence of death and life.
Thomas Aquinas