“To become a happy person have a clean soul, eyes that see romance in the commonplace, a child’s heart, and spiritual simplicity.”

Source: Uniqueness of Zakir Husain and His Contributions (1997), p. 25.

Reported in Josiah Hotchkiss Gilbert, Dictionary of Burning Words of Brilliant Writers (1895), p. 246

1840s, Heroes and Hero-Worship (1840), The Hero as Divinity

To Mme. Streicher, in 1817, or 1818, after having dismissed an otherwise good housekeeper because she had told a falsehood to spare his feelings. in Beethoven: the Man and the Artist, as Revealed in his own Words http://www.fullbooks.com/Beethoven-the-Man-and-the-Artist-as-Revealed2.html by Ludwig van Beethoven, edited by Friedrich Kerst
Attributed
Variant: Anyone who tells a lie has not a pure heart, and cannot make a good soup.

Source: Dancing in the Flames (1997), p. 221

Source: Lolita

XXI. That the Good are happy, both living and dead.
On the Gods and the Cosmos
Context: Souls that have lived in virtue are in general happy, and when separated from the irrational part of their nature, and made clean from all matter, have communion with the gods and join them in the governing of the whole world. Yet even if none of this happiness fell to their lot, virtue itself, and the joy and glory of virtue, and the life that is subject to no grief and no master are enough to make happy those who have set themselves to live according to virtue and have achieved it.

The Sixteenth Revelation, Chapter 67
Context: Then our Lord opened my spiritual eye and shewed me my soul in midst of my heart. I saw the Soul so large as it were an endless world, and as it were a blissful kingdom. And by the conditions that I saw therein I understood that it is a worshipful City. In the midst of that City sitteth our Lord Jesus, God and Man, a fair Person of large stature, highest Bishop, most majestic King, most worshipful Lord; and I saw Him clad majestically. And worshipfully He sitteth in the Soul, even-right in peace and rest. And the Godhead ruleth and sustaineth heaven and earth and all that is, — sovereign Might, sovereign Wisdom, and sovereign Goodness, — the place that Jesus taketh in our Soul He shall never remove it, without end, as to my sight: for in us is His homliest home and His endless dwelling. And in this He shewed the satisfying that He hath of the making of Man’s Soul. For as well as the Father might make a creature, and as well as the Son could make a creature, so well would the Holy Ghost that Man’s Soul were made: and so it was done. And therefore the blessed Trinity enjoyeth without end in the making of Man’s Soul: for He saw from without beginning what should please Him without end.