From the Stromata (Miscellanies) II, 4:
Should one say that Knowledge is founded on demonstration by a process of reasoning, let him hear that first principles are incapable of demonstration; for they are known neither by art nor sagacity. For the latter is conversant about objects that are susceptible of change, while the former is practical solely, and not theoretical. Hence it is thought that the first cause of the universe can be apprehended by faith alone. For all knowledge is capable of being taught; and what is capable of being taught is founded on what is known before.
One reason Patristic studies are fruitful is that the Fathers met many of the same philosophical objections to Christianity (to theism in general, in many cases) that we do today. We, like geese waking up in a new world every morning (well, that’s what my mother used to say) think that the assaults are new, but they are not. They were especially important to those who lived in Alexandria, such as Clement and Origen, where philosophy was deeply rooted. It’s not an accident that the first full-scale defence of Christianity was Origen’s Contra Celsum.
In Clement’s case here he is defending against an idea that we hear from atheists today: that they, uniquely it seems, consider things from pure reason while everyone else do not. Clement’s comeback is that the first principles are unknowable by reason or investigation. I would put it differently: I think that both sides are using reason but differing premises. To take the atheists as correct is not as much to say that their logic or reasoning is superior but that their premises are correct. Although I agree with Clement that many of the first premises are unknowable, a more immediate problem is that the atheists’ philosophical extrapolations from the science are faulty. One need only consider the multiple extrapolations from evolution–something that has bedevilled the theory from Darwin onward–to see that this is so.
On a lighter note, we can see Clement’s own logic on the subject of earrings. Although my Pentecostal bretheren will wince at the memory of legalism, we have certainly seen this come to pass:
The Word prohibits us from doing violence to nature by boring the lobes of the ears. For why not the nose too? (The Instructor, III, 11)