Secular humanists are largely the product of the enlightenment and modern scientific rationalism yet their roots run deep. The bible speaks of God’s displeasure during the days when “everyone did what was right in his own eyes” (Jud. 17:6). The fifth century BC Sophist Protagoras famously declared “Of all things the measure is man,” and this still seems a suitable credo for today’s humanists.
Epistemology is the branch of philosophy concerned with questions about knowledge and belief and related issues such as justification and truth.  A major problem for the secular humanist is their theory of knowledge. The secular humanist will invariably assert scientific consensus as the final word. According to Webster’s scientism is “an exaggerated trust in the efficacy of the methods of natural science applied to all areas of investigation.” For example, Bertrand Russell wrote:
While it is true that science cannot decide questions of value, that is because they cannot be intellectually decided at all, and lie outside the realm of truth and falsehood. Whatever knowledge is attainable, must be attained by scientific methods; and what science cannot discover, mankind cannot know.
Yet this precept is self-refuting in that it is not itself established by science via data from controlled repeatable experiment. Science is limited. For instance, the scientific method cannot even discover why I baked brownies yesterday. Perhaps I made them for a party or a church social? There is a truth to be known, yet short of me telling, science is impotent. God is a person, well actually three persons… much like the reason why I baked brownies, there is truth to be known about God, but it is up to him to reveal it.
Furthermore, science simply presupposes the rules of mathematics and logic, the uniformity of nature and the rational intelligibility of the universe. In fact, science is dependent on them as articles of faith. Yet given atheism, there are no epistemological grounds to assume a rational universe. Albert Einstein once marveled, “The most incomprehensible thing about the universe is that it is comprehensible.” However, theists believe that reality can be described with humanly derived equations because our minds are the product of the ultimately rational God who set reality into motion. Science is dependent on the theistic interpretation of an orderly cosmos. Thus, there is a profound logical incoherence that undermines all of naturalism’s attempts to answer ultimate questions.
…to be continued
 Carol Poster. “Protagoras (fl. 5th C. BCE).” The Internet Encyclopedia of Philosophy. April 27, 2005. http://www.iep.utm.edu/protagor/ (accessed 10 26, 2010).
C. Stephen Evans, Pocket Dictionary of Apologetics & Philosophy of Religion (Downers Grove, Ill.: InterVarsity Press, 2002), 39.
 Merriam-Webster’s Collegiate Dictionary. Eleventh ed., s.v.”scientism.”
 Bertrand Russell. Religion and Science (Oxford: Oxford University Press, 1997), 243.
 Nancy Pearcey. Total Truth: Liberating Christianity From Its Cultural Captivity. (Wheaton,Il: Crossway Books, 2004), 43.