Principles of contract at law and in equity [electronic resource] : being a treatise on the general principles concerning the validity of agreements, with a special view to the comparison of law and equity / by Frederick Pollock of Lincoln's Inn, Esq., barrister at law ; Corpus Professor of Jurisprudence in the University of Oxford ; Professor of Common Law in the Inns of Court ; late Fellow of Trinity College, Cambridge ; and Honorary Doctor of Laws in the University of Edinburgh.