There is a fine line between a realist and a defeatist.
In many cases a realist sees a challenge, attempts to solve it using logic and hopefully dependable data without trying to influence the solution with subjective predictions but with cautious confidence and optimism.
A defeatist sees a challenge, attempts to solve it using logic and hopefully dependable data trying not to influence the problem with subjective predictions but does not have any confidence or optimism and deems the exercise is a failure before leaving the gate.
One pushes forward believing there's always a way and one can't get out of the morass to give it a go.