Nor let it be feared that erroneous deductions may be made from such recorded facts: the errors which arise from the absence of facts are far more numerous and more durable than those which result from unsound reasoning respecting true data.

Charles Babbage (1791-1871) English mathematician, computer pioneer, philosopher

On the Economy of Machinery and Manufactures, ch. 7 (1832)
    (Source)

Sometimes paraphrased, "Errors using inadequate data are much less than those using no data at all."