Goodwin speaks of himself as having to contend in a manner with the whole earth' (dedication to "Cata-Baptism"). His ideas were often anticipations. His rational temper made him the opponent of Seekers and Quakers, and gave him some affinity with the Cambridge Platonists. He rejected the distinction allowed by Acontius, between tolerance of error in fundamentals and in other points. He would have men 'call more for light and less for fire from heaven' (epistle in "Satan's Stratagems", 1648). In his "Divine Authority of the Scriptures Asserted" (1648), which won the commendation of Richard Baxter, he maintains, anticipating George Fox and Robert Barclay, that the word of God 'was extant in the world, nay in the hearts and consciences of men, before there was any copy of the word extant in writing.' In his "Pagans Debt and Dowry" (1651; 1671, a reply to Thomas Barlow), which led to a controversy with Obadiah Howe, he argues that without the letter of the gospel heathens may be saved.