The principle of empirical verifiability by David Hume is flawed.

Con: Meaningful by what standards? What Hume is trying to argue is that empirically verifiable claims are meaningful in the search for TRUTH, and that without this ability we are almost always proven wrong. Meaningful by the standards of everyday language users, including philosophers. In other words, the only truth that can be obtained is through the human lens, and since the human lens has produced synthetic a priori concepts, i.e. love, justice, truth, being, etc. Hume's theory of language is flawed. In other words, as an analysis of what has meaning, Hume's theory fails miserably because it fails to account for synthetic a priori judgments that humans consider to have meaning. Truth is secondary, and it is not an accurate goal to aim at in epistemology. Rather, the philosopher is aiming at what CAN be known by humans. Con: If you told me that there was a rabbit in what appeared to be a rabbit hole, your claim would have already been empirically verified in several ways. We see a hole, in the ground, and either recognize it having seen a rabbit hole before, or else we recognize it as a hole in the ground that looks like other animal burrows and is about the size for a rabbit, which we have both seen. One of the major flaws in Hume's theory lies in this very point, which is why Ayer modified Hume's theory in the 20th century. The rabbit has not been verified, rather, there is evidence for the existence of a rabbit. Ayer's theory states that things that are verifiable in principle are meaningful, which would obviously include the rabbit example. However, Hume's theory excludes this example until the rabbit has been directly verified. Con: Additionally, requiring empirical proof in the manner of David Hume does not block fringe scientific theories, it simply relegates them to their proper place (read: FRINGE) until they can be proved. Once again, this type of example is why Ayer modified Hume's theory of meaning in order to include those entities that are only verifiable in principle. Since Ayer's theory is better formulated to include these exceptions, Hume's theory is flawed. Con: Finally, to address Hume's claims on religion (you really pulled out all the stops for this one, eh?), it is wrong to say that terms like God, Satan, and the soul are meaningless. This is not what he claims at all. Hume has a great deal to say about the empirical viability of religion, but since you are currently focused on meaning, I will respond to that. At the risk of oversimplifying, our concept of the Judeo/Christian/Islamic God is an infinite and all powerful being. The meaning that we attach to this concept is simply our minds taking the idea of "powerful" and "really really big" and stretching them both out to infinity, making omnipotent and infinite structures of God in our own minds. Since you admit that the concept God has meaning, I will point out the source of error in Hume's reasoning. To state that we (humans) can grasp the concept of infinity or omnipotence based on our finite experience clearly defies reason and everyday experience. In other words, we are never able to experience infinite, yet we are able to assign certain entities the quality of infinity. In other words, we are able to come up with synthetic a priori judgments that clearly have meaning. Aside from the concept of God, an exponential function such e to the x is clearly infinite. We can clearly understand and apply the concept of infinite without ever actually experiencing it. Hence, we are able to imbue terms with meaning that are not 'put together' from various empirical sources. Con: "What never was seen, or heard of, may yet be conceived; nor is any thing beyond the power of thought, except what implies an absolute contradiction. But though our thought seems to possess this unbounded liberty, we shall find, upon a nearer examination, that it is really confined within very narrow limits, and that all this creative power of the mind amounts to no more than the faculty of compounding, transposing, augmenting, or diminishing the materials afforded us by the senses and experiences. Another more powerful example would be that of Gabriel's Horn, which seems to be a direct contradiction to common experience. If you take the function 1/x and then rotate 2pi around the x axis, and then take the integral of that function from 1 to infinity, you find a form that has finite volume but infinite surface area. This conclusion clearly follows the logical rules of calculus, but defies everyday experience. Hence, once again, one must admit that Hume's theory is flawed since our minds are able to come up with an entity that cannot exist in the physical universe.