Here are two choice quotes directly from the pen of Gordon Clark, as written about in a previous post:
... The important question is not whether or not the Bible is true, but whether or not all knowledge is deducible by reason, i.e. by logic alone.
Now, the history of philosophy ... have convincingly answer in the negative.
.. reason without faith not only provides no religion, it supports no knowledge of any kind. ...
[Gordon H. Clark, Religion, Reason and Revelation. In The Works of Gordon Haddon Clark, Vol. 4 (Unicoi, TN: Trinity Foundation, 2004), 143]
Any discussion of man's mind and powers, to be at all Biblical, must take into account the effects of sin. Calvin, Hodge, and Machen were keenly aware of this. ...
[Quoting Machen with approval] ... So our reason is certainly insufficient to tell us about God, unless he reveals himself; but it is capable (or he would be capable if it were not clouded by sin) of receiving revelation when once it is given.
[Clark, Religion. In Works Vol. 4, 179]
As we can see from these two quotes, Van Til's charge that Clark thinks that reason is unaffected by sin whatsoever is entirely baseless. Perhaps if Van Til and the Van Tillians aren't so eager to demonize Clark then we they would be able to more critically engage the writings of Gordon Clark instead of putting up strawmen and misrepresentation of "the enemy."
Unlike them, I hope to do justice to Van Til's writings. Although analyzing Van Til's thought would not be a high priority, when I critique Van Til, I will attempt to represent him correctly, most definitely much better than the misrepresentation of Clark by Vantillians.