Father of English Hymnody" Watts wrote over 750 hymns, including "When I Survey the Wondrous Cross," "O God, Our Help in Ages Past," "I Sing the Mighty Power of God," "Alas, and Did My Savior Bleed," and "Joy to the World," many hymns of which are still favorites in the Baptist Hymnal. Watts also wrote a book on formal logic which used at Oxford for over a century as its standard text on beginning logic.
Among the many monographs Watts authored was a book entitled The Ruin and Recovery of Mankind (1740). In it Watts explored the subject of Adam's Fall and the consequences upon the entire human race along with the redemptive recovery God gave His fallen creatures through His Son and His work on the cross. Watts employed a question/answer format, with question number 16 stated as follows:
XVI. What will be the State and Condition of that large Part of Mankind who die in Infancy under any of the Dispensations of the Covenant of Grace? (p.292)1
Toward the question of dying infants who belonged to parents of heathen households, Watts answers in part:
"Upon the whole therefore, the State of Non-existence, to which we here suppose them to be reduced after Death, is much more probable, being the least Demerit of imputed Sin, or an everlasting Forfeiture of Life, and a sort of endless Punishment without Pain" (p.299)
"Neither have we any Intimations from Scripture, that all the Bodies of Infants will be raised again at the Great Day, in order to come into Judgment... .
"Mere imputed Sin, without actual Transgression, is the least and lowest sort of Guilt that can be; and therefore it is highly probable, a righteous and merciful God will inflict on them the least and lowest sort of Punishment threatened to Sin, i. e. Death in the mildest sense of it, or an universal and eternal Destruction of Soul and Body, which are forfeited by Sin" (p.300)
Thus, Watts reasoned the infants dying in infancy belonging to non-Christians would be annihilated upon death since no actual sins were committed. Even so, the infants were nonetheless tainted with Adam's sin and therefore faced permanent extinction, what Watts dubbed the "lowest" and "mildest" form of punishment.
So far as the dying infants of covenant believers were concerned, however, Watts offered more hope:
But the Infant-Offspring of those who have repented and accepted of the Covenant of Grace, are, in my Opinion, included in the Blessings of the Covenant of Abraham, which come upon Gentile Believers and their Seed... . And therefore there is much Reason to believe from many places of Scripture, that as they have a Share in this Covenant of Grace and the Blessings thereof through the Faith of their Parents, being incapable to put forth an Act of Faith themselves, so they shall be raised again to an eternal Life of Holiness and Happiness together with their Parents, as the Sons and Daughters of Abraham who have God for their God" (pp.304-305)
According to Issac Watts, the eternal destiny of infants dying in infancy was two-fold. For covenant believers (i.e. the elect and their elect infants), Watts offered firm hope based upon his understanding of Scripture and reason that Christian parents will see their children again in glory.
As for the dying infants of the non-elect, no hope remained. It would be as if they had never been born.
Watts' logic pushed him to conclude that some infants dying in infancy simply were not of the elect. Yet instead of judging reprobate infants to the fires of hell where Scripture speaks of reprobates eternally dwelling, Watts pulls a theological rabbit out of the hat by leaving in the dust of the earth reprobate infants like so many dead pigs, cattle, and horses:
“Upon the whole, the Opinion of the Salvation of all Children, as it has no countenance from the Bible, so it has no foundation in the Reason of Things... . The Scripture brings down the infants of wicked parents to the grave, and leaves them there, and so do I. The Scripture has not provided any resurrection for them, neither can I do it” (p.314).
1I modernized the spelling here and in all quotes below for easier reading