Sentence:  This circumstance in the patient 's case plus the fact that his tactual capacity remained basically in sound working order constitutes its exceptional <WSD>value</WSD> for the problem at hand since the evidence presented by the authors is overwhelming that , when the patient closed his eyes , he had absolutely no spatial ( that is , third-dimensional ) awareness whatsoever . 
Meaning of the word marked with <WSD> tags:  the quality (positive or negative) that renders something desirable or valuable