*Lessons in Truth* (1894) by H. Emilie Cady is a New Thought spiritual instruction manual, part of the late-19th-century American metaphysical tradition that gave rise to movements like Unity. Its core argument is that God is an omnipresent, all-good substance permeating all reality, and that humans can consciously access this divine power through practiced mental and verbal techniques — specifically, the repetition of "affirmations" (positive declarations of spiritual truth) and "denials" (rejections of the reality of evil, illness, or lack). Cady presents four master affirmations asserting God's omnipotence, one's unity with God, one's perfect spiritual nature, and divine guidance of one's will, claiming that memorizing and repeating these can heal the sick, dissolve material obstacles, and manifest desired outcomes without reliance on external human effort. A distinctive feature is Cady's pragmatic, almost prescriptive tone: she offers concrete guidance on which technique suits which personality type (e.g., affirmations for the timid and doubtful; denials for the self-confident or unforgiving), and she frames the entire system as operating through precise, impersonal spiritual laws rather than divine favoritism or prayer in the conventional sense. The work's central claim — that affirming a truth "brings it into manifestation" not by changing God but by aligning the practitioner with laws already operating toward their good — anticipates what would later be popularized as the "law of attraction."