The advantages of truth over untruth, reality over falsehood, appear so obvious that it seems inconceivable that anyone would even draw it into question, much less suggest the opposite - that untruth may in fact be preferable to truth. But that is just what German philosopher Friedrich Nietzsche did - and so perhaps the advantages of truth are not as clear-cut as we normally assume.
Nietzsche's delving into the nature of truth were part of an overall program that took him on investigations into the genealogy of a variety of aspects of culture and society, with morality being among the most famous with his book On the Genealogy of Morals (1887). Nietzsche's goal was to better understand the development of "facts" (moral, cultural, social, etc.) taken for granted in modern society and thereby achieve a better understanding of those facts in the process.
In his investigation of the history of truth, he poses a central question which he believes that philosophers have unjustifiably ignored: what is the value of truth? These comments appear in Beyond Good and Evil:
The will to truth which will still tempt us to many a venture, that famous truthfulness of which all philosophers so far have spoken with respect - what questions has this will to truth not laid before us! What strange, wicked, questionable questions! That is a long story even now - and yet it seems as if it had scarcely begun. Is it any wonder that we should finally become suspicious, lose patience, and turn away impatiently? That we should finally learn from this Sphinx to ask questions, too? Who is it really that puts questions to us here? What in us really wants "truth"?"
"Indeed we came to a long halt at the question about the cause of this will - until we finally came to a complete stop before a still more basic question. We asked about the value of this will. Suppose we want truth: why not rather untruth? and uncertainty? even ignorance?"
What Nietzsche is pointing out here is that philosophers' (and scientists') desire for truth, certainty, and knowledge instead of untruth, uncertainty, and ignorance are basic, unquestioned premises. However, just because they are unquestioned does not mean that they are unquestionable. For Nietzsche, the starting point of such questioning is in the genealogy of our "will to truth" itself.