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Ernst Mech

cording to common scnsc, both scicntists and historians gather rclc-vant information, which thcy cali “cvidcncc,” infcr "hypotheses" from that “cvidcncc,” test them in terms of “cvidcncc,” and draw conclu-sions compatiblc with the prcpondcrancc of ”cvidencc,” and unęontra-dictcd by any unquestionabIy reliablc “cvidcncc." Mach, likc most phenomenalists, howcver, liad littlc usc for the notion of "cvidence” at all. Theories wcrc to help understand the appcaranccs; appcaranccs wcrc not “cvidcnce" for theories. Or to put the matter anolher way the “cvidcnce” has suggested that Mach blandly believed that all “_cvj. dcnce” equaUy supported all theories. “The forciblc rcduction of all appcaranccs to what is mcchanical sccms unncccssary sińce the sanie dcgrcc of eviden.ee can be foiind for what is nonmechanical. That there arc masses, contact scrics, chcmical equivalents arc insights with the same dcgrcc of evidcnce.”⁴⁷

Machs stand with respcct to the usc of modcls in science was not as hostilc as subsequcnt philosopKćrs of science havc supposedlTTie himsclf frccly uscd both mathematical and mcchanical modcls in his own cxpcrimcntal work. His doubts with respcct to mathematical modcls, espccially thosc conccrning four-dimensional spacc, related to their deviation from what could be obscrvcd and their lack of sim plicity. His second thoughts about mechanical models wcrc doscly associated with his Iow opinion of the atomie theory and mcchanistic cxplanation in generał.

Ludwig Boltzmann in his article on “Modcls” in the elcventh cdi-tion of the Eneyelopedia Britannica presented Machs views on suiting the type of model to the particular branch of physics and on the pro-visionaI naturę of models:

Another phcnomcnology in the widest scnsc of the term, maintaincd espccially by E. Mach, gives less promincncc to maihcmatics, but con-siders the view that the phenomena of motion arc csscntiully morc funda-mental than all the others to havc bccn too hastily taken. It rather empha-sizes the prime importancc of dcscription in the most generał terms of the various spheres of phenomena, and holds that in cach sphcrc its own fundamenta! law and the notions dcrived from this must be employed. Analogies and clucidations of one sphcrc by another—c.g., hcat, elcctricity, etc.—by mcchanical conccptions, this theory regards as mcrc cphcmcral aids to per* ceprion, which arc ncccssitatcd by historical dcvelopment, but which in coursc of timc cither givc place to others or cntircly vanish from the domain of scicncc.^4,,

Philosophy of Science

Mach dcvclopcd and namcd scvcral mcthodological principlcs; their titlcs clearly indicatcd what most of them wcrc about: (i) principlc of the adjusuncut of thoughts to facts, (2) principlc of the adjustment of thoughts to cach other, (3) principlc of continuity, (4) principlc of compensation, (5) principlc of permancncc, (6) principlc of variation, and (7) principlc of suflf.cient diffcrcntiation/‘^t> Ii would be unfair to assert that these principlcs have lackcd influence on scicntists or phi-losophcrs of science. It would be morę accurate to say that they have gcnerally lackcd influence under the titlcs that Mach gavc them. Somc of them, indeed, went back to Francis Bacon and Galileo, and others wcrc narrowly tied to Mach’s phenomenalism. His best remembered one was probably his principlc of continuity, which he also callcd “the principlc of broadest possiblc generalization”:

When oncc the inquiring intcllcct has formed through adaptation, the habit of connccting two things, A fit Ii. in thought, it tries to retain this habit as far as possiblc, cvcn wherc the circumstances arc slightly altcrcd. Whcrevcr A appears, B is added in thought. The principle thus cxprcssed, which has its root in an effort for cconomy, and is particularly noticeable in the work of the great invcstigator$ may be termed the principlc of continuity.⁶⁰

Last and perhaps least, Mach gavc a name to a particular typc of cxpciimcntation. That name and the typc of expcrimentation have sińce bccomc quitc popular.

The thought cxperimcnt is a ncccssary precondition of physical c.xperi-ment. Evcrv cxpenmcntcr, cvcry discovcrcr must havc in his head the arrangement which is to be carricd out, bcforc he translatcs the same into action.⁵¹

It can starccly be doubted, that thought cxpcriincnts arc of importancc not only in physics but in all fields. . . .^G->

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