They can be obscured or deformed for common sense by faulty education, by cultural prejudices, by deceptive sense imagery. Philosophy, on the contrary, uses these principles critically, consciously, scientifically. Philosophy can therefore defend and communicate its knowledge. But in common sense this light does not return upon itself by critical reflection, is not perfected by scientific reasoning. It remains true, nevertheless, that all things are the subject matter of philosophy, in the sense that the philosopher takes as his angle of vision or point of view the highest principles, the ultimate causes, of all reality.
Philosophy is thus close to common sense and at the same time different from it.
It is close to common sense because it shares the universality of common sense and a common insight into the fundamental structure of reality. We might even say that philosophy grows out of common sense, and that common sense taken in its strict meaning is a kind of foreshadowing, a dim silhouette, of philosophy proper. Any philosophy, therefore, that strays very far from common sense is suspect. If it goes so far as to contradict the basic certitudes of common sense, then it is guilty of denying reality itself, and on this point common sense can pass judgment on it. I hope this short discussion has helped you understand the position of the classical realist regarding philosophy and common sense.