their maturity, this native tendency towards heterodoxy grew with his
growth and strengthened with his strength. He passed from Calvinism to
Arianism; and finally, in middle life, landed in that very broad form
of Unitarianism by which his craving after a credible and consistent
theory of things was satisfied.

On leaving Daventry Priestley became minister of a congregation, first
at Needham Market, and secondly at Nantwich; but whether on account of
his heterodox opinions, or of the stuttering which impeded his
expression of them in the pulpit, little success attended his efforts
in this capacity. In 1761, a career much more suited to his abilities
became open to him. He was appointed "tutor in the languages" in the
Dissenting Academy at Warrington, in which capacity, besides giving
three courses of lectures, he taught Latin, Greek, French, and Italian,
and read lectures on the theory of language and universal grammar, on
oratory, philosophical criticism, and civil law. And it is interesting
to observe that, as a teacher, he encouraged and cherished in those
whom he instructed the freedom which he had enjoyed, in his own student
days, at Daventry. One of his pupils tells us that,

"At the conclusion of his lecture, he always encouraged his
students to express their sentiments relative to the subject of it,
and to urge any objections to what he had delivered, without
reserve. It pleased him when any one commenced such a conversation.
In order to excite the freest discussion, he occasionally invited
the students to drink tea with him, in order to canvass the
subjects of his lectures. I do not recollect that he ever showed
the least displeasure at the strongest objections that were made to
what he delivered, but I distinctly remember the smile of
approbation with which he usually received them: nor did he fail to