Looking for an old Dabney quote

[RamistThomist]

On A Puritans Mind they used to have a Dabney t-shirt for sale and there was a Dabney quote which ran along the lines of the truth of a proposition is something about the negation of the contrary. But I can't remember the exact quote, nor where it is from.

Any help?

 

[VictorBravo]

Probably too long for a tee shirt, but sounds similar:

"A truth is not necessary, because we negatively are not able to conceive the actual existence of the opposite thereof; but a truth is necessary when we positively are able to apprehend that the negation thereof includes an inevitable contradiction. It is not that we cannot see how the opposite comes to be true, but it is that we are able to see that that the opposite cannot possibly be true."

Dabney, Systematic Theology, sect. 1, chap. 6, lecture 8[1].

 

[RamistThomist]

That's it. Thanks. I think the quote was boiled down.