Quintilian, Institutio Oratoria, Book 2, chapter 16, section 17
[17] Finally, how little the heavenly boon of reason avails those who are born dumb. If therefore we have received no fairer gift from heaven than speech, what shall we regard as so worthy of laborious cultivation, or in what should we sooner desire to excel our fellow-men, than that in which mankind excels all other living things?
Quintilian, Institutio Oratoria, Book 2, chapter 16, section 17
[17] Finally, how little the heavenly boon of reason avails those who are born dumb. If therefore we have received no fairer gift from
 heaven than speech, what shall we regard as so worthy of laborious cultivation, or in what should we sooner desire to excel our fellow-men, than that in which mankind excels all other living things?