by Robert Barclay, An Apology for the True Christian Divinity… (1678)
“ The heart is deceitful above all things, and desperately wicked. For who can with any colour of reason imagine, that that which is so hath any power of itself, or is in any wise fit, to lead a man to righteousness, whereunto it is of its own nature directly opposite? This is as contrary to reason, as it is impossible in nature that a stone, of its own nature and proper motion, should fly upwards: for as a stone of its own nature inclineth and is prone to move downwards towards the centre, so the heart of man is naturally prone and inclined to evil, some to one, and some to another. ”
