... superstitions, which, being unable to defend themselves on fair ground, raise these intangling brambles to cover and protect their weakness. Chased from the open country, these robbers fly into the forest, and lie in wait to break in upon every unguarded avenue of the mind, and overwhelm it with religious fears and prejudices. ... The idea of God, as meaning an infinitely intelligent, wise and good Being, arises from reflecting on the operations of our own mind, and augmenting, without limit, those qualities of goodness and wisdom.

Nothing is demonstrable, unless the contrary implies a contradiction. Nothing, that is distinctly conceivable, implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently there is no being, whose existence is demonstrable.

Eloquence, at its highest pitch, leaves little room for reason or reflection, but addresses itself entirely to the desires and affections, captivating the willing hearers, and subduing their understanding.

There is not to be found, in all history, any miracle attested by a sufficient number of men, of such unquestioned good sense, education and learning, as to secure us against all delusion in themselves.

There is only one vice, which may be found in life with as strong features, and as high a colouring as needs be employed by any satyrist or comic poet; and that is AVARICE.

... if you insist that the inference is made by a chain of reasoning, I desire you to produce that reasoning. The connection between the two is not intuitive. There is required a medium, which may enable the mind to draw such an inference, if indeed it be drawn by reasoning and argument. What that medium is, I must confess, passes my comprehension; and it is incumbent on those to produce it, who assert that it really exists, and is the origin of all our conclusions concerning matter of fact.

No amount of observations of white swans can allow the inference that all swans are white, but the observation of a single black swan is sufficient to refute that conclusion.