As to his character, he very obviously possessed the necessary determination and drive of any ambitious and hard mountaineer; Lord Mackay provided a good description of Raeburn, writing that he was "... physically and mentally hard as nails, trained by solitary sea-cliff climbing after birds' haunts, he was certain, unyielding and concise in every movement, both mental and physical." Mackay went on to remark that Raeburn had a capacity of grip that was astonishing: "He was possessed of strong muscular fingers that could press firmly and in a straight downward contact upon the very smallest hold."