“非邏輯關係”的意思就是沒有邏輯關係，也就是英文”it does not follow”的意思。再看下面兩例：
-- cindy lives across the street from her cousin. consequently the two have developed a warm relationship.
-- marijuana should be legalized. one of the reasons is that it serves as a pain killer for headaches, cramps, and other routine ailments, and has been used as such for thousands of years.
邏輯錯誤通常可以分為兩種：形式邏輯錯誤(formal fallacies)和內容邏輯錯誤(material fallacies)。形式邏輯錯誤來源於三段論推理形式的錯誤，這類錯誤違反三段論推理的原則，即推理的前提與結論之間缺乏必要的邏輯形式關係;而內容邏輯錯誤涉及推理的內容，即推理的前提本身不正確或不準確。上面我們分析的長者華納的四種邏輯錯誤都是屬於內容邏輯錯誤。在談邏輯錯誤之前，我們必須了解邏輯的基本類型和形式。下面我們簡單介紹歸納與演繹推理、三段論的推理形式。