The king of the skeptics, David Hume, wrote the following in his A Treatise on Human Nature:
I have always remarked, that the author
proceeds for some time in the ordinary way of reasoning, and establishes
the being of a God, or makes observations concerning human affairs; when
of a sudden I am surprized to find, that instead of the usual copulations
of propositions, is, and is not, I meet with no proposition that is not
connected with an ought, or an ought not. This change is imperceptible;
but is, however, of the last consequence. For as this ought, or ought
not, expresses some new relation or affirmation, it is necessary that it
should be observed and explained; and at the same time that a reason
should be given, for what seems altogether inconceivable, how this new
relation can be a deduction from others, which are entirely different
from it. But as authors do not commonly use this precaution, I shall
presume to recommend it to the readers; and am persuaded, that this small
attention would subvert all the vulgar systems of morality, and let us
see, that the distinction of vice and virtue is not founded merely on the
relations of objects, nor is perceived by reason.
In the same work, Hume later goes on to say:
I have objected to the system, which establishes eternal rational
measures of right and wrong, that it is impossible to shew, in the actions
of reasonable creatures, any relations, which are not found in external
objects; and therefore, if morality always attended these relations,
it were possible for inanimate matter to become virtuous or vicious. Now
it may, in like manner, be objected to the present system, that if virtue
and vice be determined by pleasure and pain, these qualities must, in
every case, arise from the sensations; and consequently any object,
whether animate or inanimate, rational or irrational, might become
morally good or evil, provided it can excite a satisfaction or
Besides demonstrating how much our language has disintegrated since Hume’s day, he makes an interesting point here about how morality works. He claims to not be able to find a moral relations of humans that are not found in external objects. For our purpose we will not attempt to prove this. We will, however, appeal to the atheist who says that the universe is ultimately only matter and energy, physics and chemistry, which in Hume’s terms equal “external relations.” From observing these external relations, we get cause and effect. Those who deny the existence of God must ultimately derive morals from external observations of cause and effect. This equals descriptions of what is. In this system, humans are complicated objects, and morals are relations between objects.
Interestingly, Hume’s common underlying motivations appears to be to weaken theism in general and Christianity in particular. But in doing so, he is so logically consistent as to pull the rug out from under the modern skeptic and atheist. For if the “eternal measures of right and wrong” are not consistent, then we are left with non-eternal measures, which equal situational and varying measures of morality. The tree that is good for shade would be morally good; the soup that tastes bad would be morally bad, “provided it can excite a satisfaction or uneasiness” as Hume describes.
Presumably almost all of us would admit this is not the case, yet atheists continue to say that we can only know what is, then turn around and tell us what ought to be. They then base morality on external actions and how these actions feel to individuals, not on some external objective measure independent of humanity. They do what Hume describes in the first quote: they start out describing what is and is not, then at some point always subtly sneak in what ought to be.