What does 'cold belief' mean?

Solution 1:

Cold here means:

• not affected by emotion; objective: cold logic. (AHD)

A cold belief, an objective unemotional belief.

Solution 2:

In the OED (Oxford English Dictionary), meaning 7d for 'cold' is

"Feelingless, cold-blooded; void of emotion."

Solution 3:

The idea of rational, unemotional analysis (of the sort scientists are supposed to specialize in) is commonly referred to as "cold", especially by people who don't like the conclusions which are drawn.

Herman Kahn, a noted defense analyst in the 1950s, specialized in thinking about the consequences and implications of defense policies dealing with nuclear warfare, and coined the phrase "thinking the unthinkable". In The Essential Herman Kahn his essay "In Defense of Thinking" includes

Critics frequently refer to the icy rationality of the Hudson Institute, the RAND Corporation, and other such institutions. I'm always tempted to reply, "Would you like a warm, human error? Do you feel better with a nice emotional mistake?"