Grammar

Take the assertion that a noun sometimes can be said to refer to an object but that a conjunction never does.

No one would construe that statement for a scientific or a metaphysical assertion.

But if I said that if we pay careful attention/ that sometimes when I use a noun in a sentence we can see that it stands for an object/ but at other times/ no such object can be found (even though it is a noun).

It might sound as if I was making a scientific or metaphysical claim.  Like if I said that in order to use the verb "to think" meaningfully in a sentence/ there would have to be subject/ but that we might not be able to establish who the subject referred to.