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."