The debate on the validity of conceptual argumentation in mathematics can be traced at least as far back as 1850s Germany -- between computational Berlin-mathematicians like Kummer, Kronecker and Weierstrass, and conceptual Göttingen-mathematicians like Dirichlet, Gauss, and Riemann. This debate intensified with Hilbert's nonconstructive proof of the Basis Theorem leading to Gordan's famous quote: "This is not Mathematics. This is Theology." This week's seminar addresses this debate from a History of Mathematics perspective, with the goal of motivating the research program of reverse mathematics.