Gallery owner: Because this painting appears in no catalog of van Gogh' s work, we cannot guarantee that he painted it. But consider: the subject is one he painted often, and experts agree that in his later paintings van Gogh invariably used just such broad brushstrokes and distinctive combinations of colors as we find here. Internal evidence, ttherefore, makes it virtually certain that this is a previously uncataloged, late van Gogh, and as such, a bargain at its price. The reasoning used by the gallery owner is flawed because it ['neglects to cite expert authority to substantiate the claim about the subject matter of the painting', 'ignores the fact that there can be general agreement that something is the case without its being the case', "attempts to establish a particular conclusion because doing so is in the reasoner's self-interest rather than because of any genuine concern for the truth of the matter", "provides no evidence that the painting is more likely to be an uncataloged van Gogh than to be a painting by someone else who painted that particular subject in van Gogh's style"]