Born in Philadelphia, Willing completed preparatory studies in Bath, England. He studied law in London at the Inner Temple then returned to Philadelphia and engaged in mercantile pursuits until 1793. A member of the common council in 1755, he became a alderman in 1759, associate justice of the city court on October 2, 1759, and then justice of the court of common pleas February 28, 1761. Willing then became Mayor of Philadelphia in 1763, then an associate justice of the Supreme Court of Pennsylvania1767 - 1777. A member of the committee of correspondence in 1774 and of the committee of safety in 1775, he served in the colonial house of representatives.
Thomas was born in 1225 at Roccasecca, a hilltop castle from which the great Benedictine abbey of Montecassino is not quite visible, midway between Rome and Naples.
Thomas describes logic as dealing with "second intentions," that is, with relations which attach to concepts expressive of the natures of existent things, first intentions.
Thomas emphasizes those passages in the Aristotelian natural writings which speak of the order of determination, that is, of what considerations come first and are presupposed to those that come later.