Theaetetus

Plato

Theaetetus

Plato (428–347 BC)

Plato's Theaetetus in the Greek text edited by John Burnet, with Harold North Fowler's English translation.


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Section 148

THEAET. The numbers between these, such as three and five and all numbers which cannot be formed by multiplying equal factors, but only by multiplying a greater by a less or a less by a greater, and are therefore always contained in unequal sides, we represented by the shape of the oblong rectangle and called oblong numbers.

SOC. Very good; and what next?

THEAET. All the lines which form the four sides of the equilateral or square numbers we called lengths, and those which form the oblong numbers we called surds, because they are not commensurable with the others in length, but only in the areas of the planes which they have the power to form. And similarly in the case of solids.

SOC. Most excellent, my boys! I think Theodorus will not be found liable to an action for false witness.

THEAET. But really, Socrates, I cannot answer that question of yours about knowledge, as we answered the question about length and square roots. And yet you seem to me to want something of that kind. So Theodorus appears to be a false witness after all.

SOC. Nonsense! If he were praising your running and said he had never met any young man who was so good a runner, and then you were beaten in a race by a full grown man who held the record, do you think his praise would be any less truthful?

THEAET. Why, no.

SOC. And do you think that the discovery of knowledge, as I was just now saying, is a small matter and not a task for the very ablest men?

THEAET. By Zeus, I think it is a task for the very ablest.

SOC. Then you must have confidence in yourself, and believe that Theodorus is right, and try earnestly in every way to gain an understanding of the nature of knowledge as well as of other things.

THEAET. If it is a question of earnestness, Socrates, the truth will come to light.

SOC. Well then—for you pointed out the way admirably just now—take your answer about the roots as a model, and just as you embraced them all in one class, though they were many, try to designate the many forms of knowledge by one definition.

THEAET. But I assure you, Socrates, I have often tried to work that out, when I heard reports of the questions that you asked, but I can neither persuade myself that I have any satisfactory answer, nor can I find anyone else who gives the kind of answer you insist upon; and yet, on the other hand, I cannot get rid of a feeling of concern about the matter.

SOC. Yes, you are suffering the pangs of labor, Theaetetus, because you are not empty, but pregnant.

THEAET. I do not know, Socrates; I merely tell you what I feel.

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Section 151

Section 152

Section 153

Section 154

Section 155

Section 156

Section 157

Section 158

Section 159

Section 160

Section 161

Section 162

Section 163

Section 164

Section 165

Section 166

Section 167

Section 168

Section 169

Section 170

Section 171

Section 172

Section 173

Section 174

Section 175

Section 176

Section 177

Section 178

Section 179

Section 180

Section 181

Section 182

Section 183

Section 184

Section 185

Section 186

Section 187

Section 188

Section 189

Section 190

Section 191

Section 192

Section 193

Section 194

Section 195

Section 196

Section 197

Section 198

Section 199

Section 200

Section 201

Section 202

Section 203

Section 204

Section 205

Section 206

Section 207

Section 208

Section 209

Section 210

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