Coolhaas, Gaspard a Protestant German theologian, was born at Cologne in 1536. After serving several churches he was appointed to Leyden in 1575; presided at the inauguration of the university of that place, and there taught theology until the arrival of William Fougereau, titulary professor. Coolhaas had several discussions with his colleagues; he maintained against Peter Cornelissen that the intervention of the civil magistrate was necessary in the election of elders and deacons. Brandt says that this was the beginning of the dissensions concerning the authority of the civil government in ecclesiastical matters. Coolhaas did not approve the dogma of absolute predestination. In 1578 the synod of Middleburg condemned his writings, but he appealed to the states-general of Holland, who confirmed the synodal sentence, and prohibited him from exercising his ministerial functions. The burgomaster of Leyden sustained Coolhaas in his heterodoxy, and, in spite of a new excommunication of the synod of Harlem, continued to pay him his allowance. After about two years he withdrew. He died in that city in 1615, leaving a large number of works, polemical or apologetic of his opinions, which are now of small account. See Hoefer, Nouv. Biog. Generale, s.v.; Biog. Universelle, s.v.