Not All Principles Are Causes
Not all principles are causes. A principle is that from which anything derives or proceeds. This definition might closely resemble a cause, yet there is a distinction. A privation, for instance, is a principle of change, but it is not a cause. There is a sense in which premises cause the conclusion, but it would be more accurate to say that they are principles of the conclusion. In the case of a privation, the difference is that a cause is more than mere non-being, which is accidental, it must be something which, in some way, is. And in the case of premises and conclusions, a cause must be a principle from which something really proceeds. Conclusions, properly speaking, only logically follow from premises.