Philosophy. He had no faith in Speeches but in Blood and Iron policy.
The role of Bismarck in the unification of Germany was as follows :
(i) War with Denmark : In 1864 Bismarck waged war on Denmark to recover Schleswig and Holstein. In this task he got help of Austria. He defeated Denmark in the war.
(ii) Austro-Prussian War : Holstein was not enough for Austria which caused war. Bismarck kept Austria alone in Europe. The whole of Europe underestimated Prussia. He easily defeated Austria in 7 weeks war. As per the Prague Treaty, Austria gave up Holstein in Germany.
(iii) War with France : Bismarck wanted war with France to recover Alsace-Lorraine. He used Spanish succession problem to create war with France. He declared Germany's Leopold as the King of Spain. Bismarck defeated France in the Battle of Sedan in 1871.