This document discusses different approaches to valuation, including their philosophical basis and advantages/disadvantages. It covers discounted cash flow valuation, relative valuation, and the efficient market hypothesis. Discounted cash flow valuation estimates intrinsic value by discounting expected future cash flows. Relative valuation compares asset prices to similar assets based on common variables. The efficient market hypothesis states markets are efficient with respect to available information and economic profits cannot be earned. Both valuation methods have advantages like forcing assumptions to be made explicit, but also disadvantages like sensitivity to input estimates.