Sentence:  Despite this danger , however , we are informed on every hand that ideas , not <WSD>machines</WSD> , are our finest tools ; they are priceless even though they cannot be recorded on a ledger page ; they are the most valuable of commodities - and the most salable , for their demand far exceeds supply . 
Meaning of the word marked with <WSD> tags:  any mechanical or electrical device that transmits or modifies energy to perform or assist in the performance of human tasks